The tick sound of a giant weta,Deinacrida rugosa(Orthoptera : Stenopelmatidae : Deinacridinae)

摘要

A ticking sound is described as the third acoustic component of the defense behaviour of the giant weta,Deinacrida rugosaBuller. The ticks occur at a mean interval of 0.36 s, but are not correlated with any movements visible to the unaided eye. The ticks contain a mean of 5.4 pulses which decrease in amplitude but which have similar waveforms and periodicities. Spectral analysis indicated that ticking sounds, as well as pulses from defensive leg-kicking stridulatory sounds, are characterised by a 12 kHz peak. It is concluded that ticking is produced by the femoro-abdominal stridulatory mechanism but that extremely small leg movements are involved.